This invention relates to low pressure accumulator conveyors of the type where cartons or other successive articles are conveyed along a surface defined by successive freely rotatable rollers which are driven from beneath by frictional engagement with a continuous belt or cable, and more particularly to accummulator conveyors of this type wherein provision is made for minimizing the friction between the rollers and any carton resting thereon which is blocked from further forward movement.
Specific examples of conveyors operating in accordance with this general principle are shown, for example, in DeGood et al U.S. Pat. No. 3,253,697 of 1966, Forsythe et al U.S. Pat. No. 3,266,617 of 1966, DeGood U.S. Pat. No. 3,420,356 of 1969 and Bodewes et al U.S. Pat. No. 4,318,468 of 1982. The conveyor mechanisms disclosed in those patents vary in complexity and mode of operation, but all are characterized by a tendency to be relatively noisy and/or by objectionable vibration in operation.